Human brain has two ‘clocks’ to help it predict the future

The human brain has two neural ‘clocks’ to help predict what will happen a split second into the future, new research finds.

While we might not be aware of it, our brains are constantly trying to predict the future – not in the sense of what is going to happen in a few years from now, but within a few milliseconds.

So, when we flick on a light switch, our brains are already predicting that light will appear suddenly because we’ve done it so many times before. The same goes for when we hear the opening chord of one of our favourite songs, with our brain knowing what the next one will be.

This, according to new research from the University of California, Berkeley, shows that our brains have two ‘clocks’: one that relies on past experiences and one that follows rhythm.

“Whether it’s sports, music, speech or even allocating attention, our study suggests that timing is not a unified process, but that there are two distinct ways in which we make temporal predictions, and these depend on different parts of the brain,” said the study’s lead author, Assaf Breska.

The research offers us a new perspective on how humans calculate when to make a move. It was discovered by analysing the anticipatory timing strengths and deficits of people with Parkinson’s disease and people with cerebellar degeneration.

Both stick up for one another

In testing, patients were shown sequences of red, white and green squares as they flashed by at varying speeds on a computer screen, and pushed a button the moment they saw the green square. The white squares alerted them that the green square was coming up.

For those with cerebral degeneration, a steady pattern resulted in high scores for them, and those with Parkinson’s scored better when presented with a more complex pattern.

Through this, the researchers connected rhythmic timing to the basal ganglia, and linked the clock based on prior experiences to the cerebellum. Both of these regions are associated with movement and cognition.

Additional findings suggest that the two keep an eye out for one another – when one of these neural clocks misfires, the other steps in to help.

“Our study identifies not only the anticipatory contexts in which these neurological patients are impaired, but also the contexts in which they have no difficulty, suggesting we could modify their environments to make it easier for them to interact with the world in face of their symptoms,” Breska said.